If you're familiar with WIN9x's Scandisk, Error Checking (chkdsk) is XP's
"scandisk". As for how often you would use it, there is no set time interval
for when to use it..........a time when I definitely run chkdsk is prior to
defragmenting the volume.
Some people recommend weekly, while others recommend biweekly or monthly. I
run it weekly, always while enabling the option to fix file errors. On the
first Saturday of each month, I run it with the "check for bad sectors"
option enabled as well. You should always run it if XP has trouble loading,
reading, modifying, deleting, or saving a file on your hard disk, or if a
program keeps hanging for no apparent reason.